Neuropsychiatry of Nutritional Disorders

Question 1

What is malnutrition?

Answer 1

A state of nutrition in which deficiency or excess of energy, protein and other nutrients causes measurable adverse effects on tissue,body form, function, and clinical outcome’ (Joosten and Hulst 2008)

Question 2

What are the two routes to malnutrition?

Answer 2

1. Insufficient or inappropriate food intake
2. Normal intake, but failures of digestion/metabolism

Question 3

What are the two major categories of malnutrition?

Answer 3

1. Marasmus – calorie deficiency
2. Kwashiorkor – protein deficiency

Question 4

What are characteristics of Kwashiorkor?

Answer 4

-swelling of legs (oedema)
-sparse hair
-moon face, with little interest in surroundings
-flaky appearance of skin
-swollen abdomen
-thin muscles, but fat present

Question 5

What are the characteristics of marasmus?

Answer 5

-normal hair
-old man or wizened appearance
-thin limbs with little muscle or fat
-very underweight body

Question 6

How is malnutrition classified?

Answer 6

-Waterlow criteria (1972): measures based on weight and height compared against population norms

-WHO criteria (1999): number of SDs between observed and expected values for weight and height, (-2 = moderate, -3 = severe).

Question 7

What is acute starvation?

Answer 7

CNS is usually among the last body systems to be affected. May be delirium and encephalopathy, followed by coma.

Question 8

What is chronic starvation?

Answer 8

malnutrition – not fatal, but causing long-term problems. More relevant to neuropsychiatry

Question 9

What is pyloric stenosis?

Answer 9

-Pyloric stenosis is a narrowing of the pylorus, the opening from the stomach, into the small intestine.
-a brief period of starvation in early infancy, is unrelated to socioeconomic conditions, and is easily correctable”
(Klein et al 1975)
-History of pyloric stenosis associated with short-term memory and attentional deficits

Question 10

What were the findings of the Barbados Nutrition Study
(BNS, Galler et al 1989, 2012)?

Answer 10

-40 year longitudinal study
-Individuals with normal birth weight but period of protein-energy malnutrition in first year of life
-Early malnutrition associated with:
Attentional deficits
Hyperactivity
Lower IQ and increased prevalence of learning disability
Subtle motor deficits

Question 11

What are specific nutritional deficiencies?

Answer 11

-Arise when diet is deficient in one or more nutrients but adequate for others
-Micronutrients – vitamins, minerals, trace elements
-Macronutrients – proteins, fats, carbohydrates

Question 12

What is thiamine (B1) deficiency?

Answer 12

-Strongly associated with alcohol dependency
Poor diet
-Alcohol compromises the absorption and utilisation of thiamine
Approx 30% of alcoholics are thiamine-deficient
-Also seen in malabsorption syndromes and conditions that involve protracted vomiting

Question 13

What are B1 rich food?

Answer 13

-green peas
-tomatoes
-sunflower seeds
-brussel sprouts
-black beans
-macadamia nuts
-spinach

Question 14

What is beriberi?

Answer 14

Weakness, lassitude, myalgia, cardiac problems

Question 15

What is ‘wet beriberi’?

Answer 15

– dominated by cardiac failure and oedema

Question 16

What is ‘dry beriberi’?

Answer 16

dominated by neurological features – peripheral nerve damage leading to sensory and motor deficits, muscle wasting

Question 17

What is the classic triad for Wernicke’s encephalopathy (WE)?

Answer 17

-Acute presentation – classic ‘triad’:
Confusion
Cerebellar ataxia
Opthalmoplegia
Treat with high dose parenteral thiamine
-Often fatal if untreated
85% of survivors of alcoholic WE progress to Korsakoff syndrome (KS)
Outcomes better in non-alcoholic WE

Question 18

What are the brain regions for wernicke’s encephalopathy?

Answer 18

-Mammillary bodies
-Thalamus
-Superior colliculi
Walls of the third ventricle
Pons, medulla, brainstem
Cerebellar vermis

Question 19

What is Korsakoff syndrome?

Answer 19

-Characterised by confabulation
-Not reversible by thiamine
May require long-term specialist care
-Atrophy of mammillary bodies seen in approx. 80%

Question 20

How does niacin (B3) deficiency present?

Answer 20

Pellagra
Dermatitis
Diarrhoea
Dementia (but psychiatric symptoms v. variable)
(Death)

Question 21

What are vitamin B3 rich foods?

Answer 21

-poultry
-spinach
-peanuts
-fish
-potatoes
-liver
-tomatoes
-mushrooms
-meat

Question 22

What is B12 deficiency?

Answer 22

-Common (2 – 12% in first world, approx. 30% in developing countries), higher in elderly
-Involved in myelin production (as is folate)
-Loss of vibration sense
-Subacute combined degeneration of the spinal cord

Question 23

What does the subacute degeneration of the cord in B12 deficiency indicate? What do patients present with?

Answer 23

Affects dorsal and lateral columns of the cord

Causes sensory disturbance (numbness, tingling, loss of sensation)

If untreated, progresses to motor deficits – spasticity, paraplegia, ataxia

Potentially reversible with B12

Question 24

What effect does nitrous oxide have on B12?

Answer 24

-Inactivates B12
-Use as ‘party drug’ leading to rise in cases of subacute combined degeneration of cord in otherwise healthy young people

Question 25

What is folate deficiency?

Answer 25

Acts together with B12 in metabolic processes
Effects of deficiency overlap with B12
Prevalence rates around half that of B12

Neural tube defects in fetus
Folate supplementation standard in pregnancy in many countries

Also associated with depression

Question 26

What is cerebral folate deficiency (CFD)?

Answer 26

-Normally CNS folate concentration > blood concentration due to active transport(AT) across blood-brain barrier
-Impairment of AT can lead to CFD, even when plasma folate is normal
-CFD defined by low CSF 5-methyltetrahydrofolate (5-MTHF)
-Has been found in a range of rare (genetic and mitochondrial) diseases
-Pyramidal spasticity, cerebellar movement disorders and intellectual disability most common clinical features (Masingue et al, 2019)

Question 27

What did Raemekers et al (2016) argue were the distinct CFD-related syndromes?

Answer 27

Autistic
Schizophrenic
Spastic-ataxic
Epileptic
(more work needed)

Question 28

What is vitamin C deficiency characterised of?

Answer 28

-Poor wound healing
-Severe joint and muscle pain
-Dental avulsion
-Oedema
-Spontaneous haemorrhage
-Fatigue, weakness, extrapyramidal (Parkinsonian) symptoms

Question 29

What is scurvy?

Answer 29

-Scurvy is a clinical syndrome resulting from vitamin C deficiency. –Not eating enough fruits and vegetables is the main cause of the disease. Left untreated, scurvy can lead to bleeding gums, loosened teeth and bleeding under your skin.
-Now very rare in developed world – usually only encountered in states of severe self-neglect (e.g. in dementia)

(from NHS website/NIH)

Question 30

What is vitamin D deficiency?

Answer 30

-Very common: as high as 50% even in developed countries
-Mostly synthesized in skin under sunlight
Also oily fish, meats, eggs
-Lack of sunlight is main risk factor
-Associated with depression, schizophrenia, -Parkinsonism, dementia
-Relevance/role unclear
-CNS effects of Vit D deficiency may be due to hypocalcaemia (low calcium)

Question 31

What is calcium deficiency?

Answer 31

-Bones and teeth – poor development, brittle, poor fracture healing
-Neuromuscular hyperexcitability triad:
-spasm
-tetany
-hyperreflexia
-Also depression and acute confusional states
-(Magnesium deficiency causes very similar symptoms

Question 32

What is iron deficiency?

Answer 32

-Commonest of all nutrient deficiencies
Approx 30% in developed countries, close to 100% in vulnerable populations

-Microcytic anaemia
-Weakness, fatigue, low mood

-More common than would be expected by chance in mood disorders and developmental conditions (autism, ADHD)
-Not clear why (? Direction of causality)

Question 33

What is zinc deficiency?

Answer 33

-Zinc deficiency can be inherited or acquired and typically presents with infectious, inflammatory, gastrointestinal, or cutaneous involvement.
-Acts together with Vitamin C, deficiency symptoms are similar to those of Vit C deficiency but milder
-When treating Vit C deficiency, advisable to also give Zinc
-Some of the more common symptoms include loss of or diminished smell and taste, poor wound healing, hair loss, roughening of skin/rashes, low libido (men), canker sores, lethargy, and deformed nails.

(latter part from NHS website)

Question 34

What is iodine deficiency?

Answer 34

-Iodine deficiency occurs when the soil is poor in iodine, causing a low concentration in food products and insufficient iodine intake in the population.
-Problem where diet depends on crops grown in low-iodine soils
-Use of iodised table salt has greatly reduced the prevalence
-Prenatal and infant iodine deficiency  short stature, spasticity, deaf-mutism, mental retardation, hypothyroidism

Question 35

What is selenium deficiency?

Answer 35

-Selenium is a mineral that can influence various systems of the body
-Often co-occurs with iodine deficiency and contributes to symptoms
-Some evidence of association with anxiety, depression, and dementia

Question 36

How can nutrients be used as treatments in neuropsychiatry?

Answer 36

-One study suggesting B vitamins reduce symptoms in schizophrenia (Firth et al 2017)

-The neurological and psychiatric associations of nutrient deficiencies suggest they may come to have a much wider role in treatment (Sarris et al, 2016)